specialk566

My Feedback: (3)

I recently acquired a slightly used (broken in) 46 la on a trainer I purchased. It runs good from mid range to wide open, but anything below that and it cuts off unexpectedly. Idle on it is horrible, it does well to idle more than 5 seconds without cutting off. Yesterday three of us spent a good two hours playing with the low end. We went from fully rich to fully lean on the low end screw with absolutley no change in performance. That air bleed carb is horrible, the engine sounds rich no matter what. I backed the low end out almost all the way when I got home and ran it. It actually idled for over 10 seconds without cutting off (goes to show that carb is junk...hint hint os). We tried different prop sizes ( 10 6, and 11 6), idle bar plugs, tank elevation, shorter fuel lines, and removed the muffler baffle. I should mention that the people working on my engine are experienced rcers and not morons who think they know what they are doing. Even a toc pilot showed up yesterday and said he had had the same problem on a 46la he tried helping someone else with. I'm not going to say what brand I prefer b/c I dont want this turning into a debate, I just want suggestions on how to get this thing running.

I find it hard to believe that these engines are marketed to newcomers, nothing will discourage them faster than not being able to fly. Os needs to go back to the drawing board, or make the old fp line. My club members claim to never have had as many problems with the fp series as the "new and improved" la series.

Thanks for your time and reading
Kerry

w8ye

My Feedback: (16)

Often times, used airplanes/engines have sat around a couple years due to lack of interest. That's why they were sold.

You probably should remove the carb and thoroughly inspect and clean it. Especially the idle circuit because it may be full of hardened oil? Then see what you have?

Good luck,

Jim

proptop

My Feedback: (8)

My LA.46 powered Bobcat would quit every time I landed (just before touch-down) until I drilled out the air bleed hole to 1/16"...Now I can adjust it like you're supposed to be able to, no more loading up.

specialk566

My Feedback: (3)

No it hasnt been run until recently. I might try drilling it out to 1/16" like proptop suggested. Right now the low end screw has no effect whatsoever on the engine. Thanks guys

Avistar23

did you try cleaning the carb up yet ?

Miloh

You must clean it first, I have a 40 size that had the same problem and a through cleaning did not fix my prob so I drilled and this did correct the prob. BUT CLEAN THE AIR BLEED HOLE FIRST!!!!!. you might not need to drill.

Miloh.

specialk566

My Feedback: (3)

Thanks for the suggestions everyone.

flapbreaker

My Feedback: (1)

I would also remove the main needle valve and then pump fuel through it just to flush it out. I know that probably isn't your problem but you never know.

When I had my first 4 stroke (Saito .91) at the field I was having a little trouble and the "old" timers came to help. All I can say is I appreciate their help but it wound up adding 3 hours until I could get the engine started again. I was following the directions and they had me going in circles. Usually the experienced start over thinking the problem and in the end it turns out to be something simple. I was at the field the other day and this guy was about ready to throw out his Saito 100 because it would always dead stick. He had had the most experienced people at the field help him with it but they couldn't figure it out. Now I am no expert. I just got my first 4 stroke but when he was cleaning up his plane to leave I noticed that he had the fuel tubing that exits the crankcase fastened down. To me it looked pinched so I mentioned it to him. He looked at it pretty sceptically but decided to loosen it up. Well needless to say he could have kissed me cause that thing runs like a top. Sorry for the long story but I have seen too many experts over look something or provide miss information. So sometimes it pays to look at the obvious. It's too bad I helped that guy I think he would have just given the Saito to me.

planemaker

looking for help with a 12 year olds science project. anything you have that would help out would help him

kerrydel

My Feedback: (2)

Wow this is spooky. :surprised Same engine, same problems, SAME NAME!!! (start Twilight Zone music ......)

Let me know if anything works. I'm just about to throw mine in the trash. Bought mine new in April for my trainer. Haven't been able to do a touch-and-go yet. Getting pretty good at dead sticks though

Kerry DelVecchio
Dunlap, IL

big max 1935

My Feedback: (9)

You should have your throttle barrel open slightly , I have not had much luck trying to set idle on air bleed types with out having it open some. Air bleed screw is just for idle mixture. Have never had to drill one in 40 years. Granted some worked better than others but they all worked . MAX H.

Miloh

Drilling made all the difference with mine as it would not idle with the mixture screw in my pocket.
In ten years this is the first for me.

Miloh.

big max 1935

My Feedback: (9)

Miloh: Did you have your carb open slightly, the air bleed screw is for setting the mixture not the speed ,that is the job of the barrel. I find it hard to believe that the thousands of air bleed carbs that the many manufactures have made over the years would have had a problem that they would not have corrected them selves. Like I have said many times on here ,when all else fails put a Perry on it, another much miss under stood item. MAX H. Old puttz

proptop

My Feedback: (8)

One of my favorite things to do is shoot touch and goes...It got pretty fustrating having my LA quit on me every time on the first touch (no go)...I also had the adj. screw so far out that I thought it was gonna fall out! I've been flyin' R/C for 30+ years, and this is the first time I've had to drill...Now it runs great! Big Max, I like the ole Perry carbs too, got a lot of old K&B's with 'em (love the backplate pumps, too bad I can't fix the leaky ones)

JohnVH

My Feedback: (38)

I have had a couple LA engines that I had to drill the air hole bigger on, try that and I bet it will work fine.

big max 1935

My Feedback: (9)

I give up on you guys, too many engine experts for me. MAX H.

Miloh

hay BIG MAX
The idle mixture screw was the problem, you see it would load up and die. The Mfg says to start with 2 turns out but i had to go out 8 turns before it would run with out a glo stick. guess what?? the screw leaves the air bleed hole at about 8 turns and has no effect at all there after but stlii slobbering fuel all over the place.
Anyway it runs fine now, could be a casting or Q.C. problem I guess.


Miloh.

big max 1935

My Feedback: (9)

When looking down your intake could you see about a 1/32 to 1/16 opening on the throttle barrel. That used to be in the directions on some engines . The air bleed screw is for fine tuning . You also may help matters with a Fox idle bar plug . The early R/C engines had nothing but the throttle barrel & we used to get them to run . Some try to get the engine to run too slow for easier landing .Try a lower pitch prop. The TN carb is a fairly new item. All makes of engines had a air bleed carb all the way up to the OS 80 . First mixture carb was the Johnson Auto-mix then came the Perry ,still the simplest one yet to set. WOW Didn't mean to rattle on ,sorry . MAX H.

Miloh

yea I checked the barrel and the opening is correct, and my idle is set so the plane is almost moving on the ground with the throttle all the way back.

Miloh.

jaka

Hi!
Strange !? All my OS LA engine equieped airplanes and my fellow friends airplanes in my club ...could have their OS LA engines standing still on tarmac with their engines idleling all day long....that with unmodified carbs!
Come on guys!!!
There is nothing wrong with the OS LA airbleed carb and never has been...you must be doing something wrong....
Some recommendations....
On a .40 OS LA (at sea level) use 5% nitro...it's enough 10% will improve performance slighly and 15% is a waist of money!

20% castor oil or a mix of synthetic oil will work fine ...but better yet is 15% Motul "Micro" (French racing oil).
Tank size:
Allways use a 240cc (8oz) fueltank with its center inline with the fuelneedle orifice.
As for glowplugs ...nothing beats an OS 8 or Enya 3 for these engines.
As for props ...a APC 11x6 is better than a 10x6 with this engine for most trainers and lowspeed airplanes...
Carb opening should be aprox 1,5-2mm open at idle...set with the radio...not with the stop screw on top off the carb

Regards!
Jan K
Sweden

big max 1935

My Feedback: (9)

Sounds good to me , jaka , but I am partial to a FOX idle bar plug & a APC 11X4 prop. Like yours, the plane won't move when idling. MAX H.

Spaceclam

on the .46 la, the carburator barrel does not screw in like on the better fx series, so by increasing or decreasing the amount of airflow, that controls the flow of fuel, not really the low end.

Miloh

doing something wrong?????? I'm flying!!!!!!!!!!!!! this is something I could not do before the mod!!!!!!!!!

I guess I could still be wrong but the ultimate gole has been reached.

Miloh.

proptop

My Feedback: (8)

Could be because it's inverted , but it would NOT stay running @ idle untill I drilled the air bleed hole. Changed plug types several times (including an O.S.#8) and 2 different fuels too. Tank location is as close to perfect as possable, and had 3 different props on it...Only thing I don't like about it is the plastic backplate. Again, if you have the air bleed screw all the way out, and it's still too rich, then it's time to take matters in your own hands and modify it a little bit! No big deal, it's not major surgery, and even O.S. is not perfect every time, just check out the other threads on LA engines vs. FP's etc.

Spaceclam

Os is perfect every time with their better engines. As far as i am concerned, they keep all the good parts for the better engines and put the bad ones into the cheaper engines.